Adaptor cartridge for mounting a second disk in a device designed to mount a first-disk cartridge

ABSTRACT

A tray is supported movably relative to a case to enable a second disk to be loaded into and unloaded from a second-disk holding recess. Positioning is performed by using second positioning holes formed through the case and tray. A turntable and a head are inserted through two second opening holes. A second-disk cartridge of thin construction, capable of holding therein the second disk in removable fashion, can be mounted in a recording/reproducing apparatus capable of mounting therein a first-disk cartridge.

This application is a continuation of application Ser. No. 08/295,288filed Aug. 24, 1994, ABN.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a disk cartridge for holding therein adisk used in a recording or reproducing apparatus for recording andreproducing business-application graphics files, computer data files,etc., or in a playback-only CD player or the like, and also relates to adisk clamping device for clamping such a disk. More particularly, theinvention relates to a disk cartridge with a sliding cover, which, witha disk contained therein, is loaded into a recording or reproducingapparatus designed for use with such a cartridge, and also relates to adisk clamping device capable of clamping a disk regardless of whetherthe disk has a hub or not.

2. Description of the Related Art

Generally, conventional disks having a center hole therein, exemplifiedin particular by compact disks and laser disks, are inserted intorecording or reproducing apparatus (hereinafter simply referred to asrecording/reproducing apparatus) without using a protective case (suchdisks are hereinafter generally called the second disk). The second diskis therefore susceptible to damage due to dust, fingerprints, etc.,which may make the recorded information unable to be read out. Thesecond disk has the further disadvantage that it is not easy to handlewhen loading it into a recording/reproducing apparatus. Furthermore,since the second disk has a center hole only (hereinafter called thesecond center hole) that can be used for mounting, therecording/reproducing apparatus needs to be equipped with a diskclamping device for clamping the second disk in place. This not onlymakes the construction of the recording/reproducing apparatus complex,but increases the height of the construction.

In view of these problems, disks for newly developed and commercializedrecording/reproducing apparatus (such disks are hereinafter generallycalled the first disk) are encased in disk cartridges (hereinaftercalled the first-disk cartridge) to prevent damage due to dust,fingerprints, etc. and to enhance the ease of handling. The first diskhas a center hub made of magnetic metal; this serves to simplify theconstruction and reduce the height of the recording/reproducingapparatus. The center hole of the hub (hereinafter called the firstcenter hole) is made to engage on the motor shaft that drives theturntable provided in the recording/reproducing apparatus, and the hubis attracted by a magnet fixed to the turntable, to clamp the first diskin place.

However, the second disk and the recording/reproducing apparatusdesigned for use with it have already established a large market, forexample, in the form of CD players and laser disk players, and as datastorage media for business-application graphics files, computer datafiles, etc. Therefore, in developing and commercializing newrecording/reproducing apparatus having increased performance such ashigher recording density, preserving compatibility with the second diskin reproduction or in both recording and reproduction becomes a majordesign consideration. To achieve this, the recording/reproducingapparatus needs to be designed so that the second disk, as well as thefirst disk encased in the first-disk cartridge, can be mounted andpositioned in place.

The following three constructions, for example, are known in the priorart for enabling the second disk to be recorded or reproduced using thesame apparatus designed for the first disk.

(1) In Japanese Laid-Open Patent Publication No. 4-362560 (the firstprior art), a recording/reproducing apparatus is described that uses twodifferent loading mechanisms, one for loading the second disk into aprescribed position and the other for loading the first-disk cartridgecontaining the first disk into a prescribed position.

(2) In Japanese Laid-Open Patent Publication No. 4-356766 (the secondprior art), a second-disk cartridge is proposed that uses an adapter hubdesigned to be compatible with the hub of the first disk in loading andunloading; this adapter hub is manually attached to the second diskwhich is then loaded removably into the second-disk cartridge. Accordingto the construction of the second prior art, either type of disk, thefirst disk with a hub or the second disk without a hub, can be mountedproperly on the turntable in the recording/reproducing apparatus.

(3) In Japanese Utility Model Publication No. 3-25336 (the third priorart), there is proposed a second-disk holding device called a diskholder, not a disk cartridge, that is capable of removably holding thesecond disk, the construction being such that the second disk held inthe holder is delivered onto the turntable when the holder case isloaded into a recording/reproducing apparatus. The holder case consistsessentially of a first moving member, which is mounted directly onto amounting part in a recording/reproducing apparatus, and a second movingmember movable relative to the first moving member. In this disk holder,a tray on which the second disk is directly mounted, and which has anopening hole (hereinafter called the second opening hole) that permitsthe insertion therethrough of the turntable and head of therecording/reproducing apparatus, is installed, for example, in rotatablefashion, to the second moving member. When playing back the second disk,for example, the tray holding the second disk thereon is moved to theturntable of the recording/reproducing apparatus for reproduction, etc.This disk holder is so designed as to preserve mounting compatibilitywith a disk holder having, for example, six trays similar inconstruction to the above-described tray, and capable of holding aplurality of second disks, each tray being arranged, for example, inrotatable fashion in the case that is mounted on the mounting part inthe recording/reproducing apparatus.

The above prior art constructions, however, have the following problems.

(1) In the first prior art, the recording/reproducing apparatus needs tobe equipped with two loading mechanisms, one for loading the second diskand the other for loading the first disk. Furthermore, the first priorart requires that a disk clamping device for clamping the second diskfrom both sides thereof be provided in the recording/reproducingapparatus at a position opposite the turntable. This makes theconstruction of the recording/reproducing apparatus complex, andincreases the size and cost of the apparatus.

In recent years, the demand for a built-in type recording/reproducingapparatus has been increasing rapidly for use in portable personalcomputers or the like, and with this trend, reducing the apparatusheight has become an important design consideration. The first priorart, however, requires the provision of a disk clamping device, whichtends to increase the height of the recording/reproducing apparatus, andhence has the problem of being unable to reduce the apparatus height.

(2) In the second prior art, no mention is made of how the mountingcompatibility can be achieved between the second-disk cartridge capableof removably holding the second disk and the first-disk cartridgecontaining the first disk. For example, no description is given of howthe positioning means, opening means for an externally exposed shutter,etc. can be designed compatible between the first-disk and second-diskcartridges.

Also, in the second prior art, the second-disk cartridge ejected fromthe recording/reproducing apparatus must be removed from the apparatusand be manually opened to remove the second disk contained therein.Furthermore, the second prior art requires that the adapter hub havingmounting compatibility with the hub of the first disk be manuallyattached to the second disk. As a result, the user may have to spendmuch time trying to attach the hub properly, or may not be able toattach it because he has not acquired enough skill to do so. Thus thesecond prior art has the problem that the convenience of operation isgreatly sacrificed.

(3) In the third prior art, the holder case is not provided with anopening hole that is exposed to the exterior thereof and that permitsthe insertion therethrough of the turntable and head of therecording/reproducing apparatus. The third prior art therefore has theproblem that unlike a disk cartridge, the second disk as contained inthe case cannot be directly placed in the recording or reproductionposition for recording or reproduction.

In the disk holder of the third prior art, a spring or like component,as a driving means for moving the second moving member relative to thefirst moving member, is installed between the first and second movingmembers, while the tray capable of directly holding the second diskthereon is attached rotatably to the second moving member. Thisessentially requires a relatively large number of component partsarranged in the height direction of the disk holder. Furthermore, thedisk holder, though designed to accommodate one second disk, isconstructed to have approximately the same size as the disk holdercapable of containing a plurality of second disks, in order to achievemounting compatibility between them. The third prior art therefore hasthe problem that the height of the disk holder cannot be reduced becauseof its construction.

Generally, to save the storing space when not in use, and to provide theconvenience of portability, it is desirable that the disk cartridgeheight be reduced as much as possible while securing a sufficient spaceto allow the disk to rotate therein when the cartridge is mounted andpositioned in the recording/reproducing apparatus. For example, fordisks about 120 mm in diameter, the cartridge height usually is reducedto 10 mm or less. In the third prior art, however, in addition to thefirst and second moving members, such component parts as a spring andtray are placed one on top of another across the height of the diskholder, as described above. The third prior art therefore has theproblem that it is extremely difficult to reduce the cartridge height toan optimum value, e.g. 10 mm or less for disks about 120 mm in diameter.

The third prior art has the further problem that unlike disk cartridges,the second disk as contained in the disk holder cannot be directlyplaced in the recording or reproduction position for recording orreproduction.

Furthermore, the following problem generally exists for the first-diskor second-disk clamping.

The recent trend in design is to reduce the diameter of the turntable toincrease the recording area near the disk center and thereby providelarger recording capacity. This, however, reduces the size of the magnetbuilt into the turntable and decreases the clamping force; the resultingproblem is that the second disk, etc. cannot be clamped firmly on theturntable, causing disk slippage, and leading to trouble.

SUMMARY OF THE INVENTION

The second-disk cartridge of this invention is for use in a recording orreproducing apparatus capable of mounting and positioning therein afirst-disk cartridge in which a first disk is rotatably held in afirst-disk holding recess formed in a first casing, and for holdingtherein a second disk having an outer diameter equal to or smaller thanan outer diameter of said first disk. The second-disk cartridgecomprises: a second casing having a second-disk holding recess forholding rotatably said second disk, and capable of being set in eitherof first and second positions, the first position that allows loadingand unloading of said second disk with respect to said second-diskholding recess, and the second position that allows mounting andpositioning of said second disk with respect to said recording orreproducing apparatus; second positioning means formed at least on oneside face of said second casing set in said second position, andidentical in form to first positioning means for mounting andpositioning said first-disk cartridge in said recording or reproducingapparatus; and a second opening hole formed corresponding to a firstopening hole formed in said first casing for permitting insertingtherethrough of a head and a turntable of said recording or reproducingapparatus, a size of said second opening hole being the same as saidfirst opening hole or larger than said first opening inclusive.

In one embodiment of the invention, said second casing comprises a casehaving a second sub-opening hole of a size not smaller than the size ofsaid second opening hole, and having therein a tray holding recess, anda tray having said second-disk holding recess formed therein, and havinganother second sub-opening hole for exposure to exterior thereof throughthe first-said second sub-opening hole in said second position, saidtray being supported in said tray holding recess movably in directionsparallel to direction of insertion into said recording or reproducingapparatus. Said second casing is set either in said first position or insaid second position by moving said tray in the directions parallel tothe direction of insertion into said recording or reproducing apparatus.

In another embodiment of the invention, the disk cartridge furthercomprises: a locking means for locking said tray in said secondposition; and driving means for driving said tray into said firstposition in interlocking fashion with an unlocking action of saidlocking means.

In still another embodiment of the invention, at least a portion of saidcase is formed from a metal plate.

In still another embodiment of the invention, the disk cartridge furthercomprises: centering means, supported rotatably in said second casing ata position opposite said turntable of said recording or reproducingapparatus, for concentrically engaging a second center hole formed insaid second disk onto a motor shaft that drives said turntable forrotation; and a magnetic member, formed from a magnetic material, fixedto said centering means and attracted by a magnet provided in saidturntable, wherein said centering means and said magnetic member do notprotrude beyond an externally exposed surface of said second casing.

In still another embodiment of the invention, said centering meansincludes a clamp base supported rotatably in said second casing at aposition opposite said turntable of said recording or reproducingapparatus, and an elastic member, fixed to said clamp base and capableof elastic deformation in a thickness direction of said second disk, forholding said second disk against said turntable, and at least one ofsaid clamp base and said magnetic member is provided with a centeringpart that engages in said second center hole of said second disk, and acenter hole that is formed concentrically with said centering part andthat engages concentrically on said motor shaft.

Alternately, the second-disk cartridge for holding therein a second diskof the invention, comprises: a case having a second sub-opening hole forpermitting insertion therethrough of a head and a turntable of arecording or reproducing apparatus, and having therein a tray holdingrecess, and a tray having a second-disk holding recess for holdingrotatably said second disk, said tray being supported in said trayholding recess and movable in directions parallel to a direction ofinsertion into said recording or reproducing apparatus to enable settingin either of first and second positions, the first position that allowsloading and unloading of said second disk with respect to saidsecond-disk holding recess, and the second position that allows mountingand positioning of said second disk with respect to said recording orreproducing apparatus, said tray further including another secondsub-opening hole for exposure to exterior thereof through the first-saidsecond sub-opening hole in said second position. At least one of saidcase and said tray is provided with second positioning means forachieving positioning thereof for mounting in said recording orreproducing apparatus.

In one embodiment of the invention, the disk cartridge furthercomprises: a locking means for locking said tray in said secondposition; and driving means for driving said tray into said firstposition in interlocking fashion with an unlocking action of saidlocking means.

In another embodiment of the invention, the disk cartridge furthercomprises: centering means, supported rotatably in said case at aposition opposite said turntable of said recording or reproducingapparatus, for concentrically engaging a second center hole formed insaid second disk onto a motor shaft that drives said turntable forrotation; and a magnetic member, formed from a magnetic material, fixedto said centering means and attracted by a magnet provided in saidturntable, wherein said centering means and said magnetic member do notprotrude beyond an externally exposed surface of said case.

In still another embodiment of the invention, said centering meansincludes a clamp base supported rotatably in said case at a positionopposite said turntable of said recording or reproducing apparatus, andan elastic member, fixed to said clamp base and capable of elasticdeformation in a thickness direction of said second disk, for holdingsaid second disk against said turntable, and at least one of said clampbase and said magnetic member is provided with a centering part thatengages in said second center hole of said second disk, and a centerhole that is formed concentrically with said centering part and thatengages concentrically on said motor shaft.

In still another embodiment of the invention, at least a portion of saidcase is formed from a metal plate.

According to another aspect of the invention, the disk clamping devicefor enabling a second disk with a second center hole to be mounted on aturntable of a recording or reproducing apparatus capable of mountingthereon a first disk with a hub formed from a magnetic material andhaving a first center hole smaller than said second center hole,comprises: a clamp base supported rotatably at a position opposite saidturntable; an elastic member, fixed to said clamp base, for holding saidsecond disk against said turntable; and a magnetic member, formed from amagnetic material, fixed to said clamp base and attracted by a magnetprovided in said turntable to attract said hub. At least one of saidclamp base and said magnetic member is provided with a centering partthat engages in said second center hole of said second disk, and acenter hole that is formed concentrically with said centering part andthat engages concentrically on a motor shaft that drives said turntablefor rotation.

According to another aspect of the invention, the disk clamping devicefor enabling a second disk to be mounted on a turntable of a recordingor reproducing apparatus having a magnet that consists of two or an evennumber of regions greater than two, adjacent regions being magnetized inopposite directions, said disk clamping device comprises: a clamp base,supported rotatably at a position opposite said turntable, for holdingsaid second disk against said turntable; a magnetic member having apermanent magnet that is fixed to said clamp base and opposite saidmagnet, and consists of the same number of regions as the even number ofregions of said magnet, adjacent regions being magnetized in oppositedirections.

In one embodiment of the invention, the disk clamping device furthercomprises an elastic member fixed to said clamp base and capable ofelastic deformation in a thickness direction of said second disk,wherein at least one of said clamp base and said magnetic member isprovided with a centering part that engages in a second center holeformed in said second disk, and a center hole that is formedconcentrically with said centering part and that engages concentricallyon a motor shaft that drives said turntable for rotation.

Thus, the invention described herein makes possible the advantages of(1) providing a second-disk cartridge which enables a second disk to bemounted and positioned in a recording/reproducing apparatus capable ofmounting and positioning therein a first-disk cartridge containing afirst disk, and which is as thin as the first-disk cartridge and iscapable of holding the second disk in removable fashion, withoutincreasing the structural complexity and the size and cost of therecording/reproducing apparatus; (2) providing an second-disk cartridgewhich enables a second disk as contained in the case to be mounteddirectly into recording or reproduction position in arecording/reproducing apparatus, and which is as thin as a first-diskcartridge and is easy to handle, the second disk being able to be loadedin or unloaded from the second-disk cartridge not only by manualoperation but in interlocking fashion with an eject action of therecording/reproducing apparatus; (3) providing, in addition to thefeature described in above (2), a second-disk cartridge which can beautomatically set into position to allow the loading and unloading ofthe second disk, just by pushing either manually or using a pin or thelike provided in the recording/reproducing apparatus a locking unit thatlocks the casing into the retracted position to allow the mounting andpositioning of the second disk in the recording/reproducing apparatus,and which enhances the ease of operation and permits furthersimplification of the construction of the recording/reproducingapparatus; (4) providing a disk cartridge having a disk clamping devicewhich is capable of automatically centering and clamping a second diskwith no hub onto the turntable of a recording/reproducing apparatus, andallows a reduction in the height of the recording/reproducing apparatus,without increasing the structural complexity, cost, etc. of therecording/reproducing apparatus; (5) providing a disk clamping devicewhich is capable of automatically centering and clamping a second diskwith no hub onto the turntable of a recording/reproducing apparatuscapable of clamping a first disk with a hub by magnetic attraction; and(6) providing a disk clamping device which is capable of centering asecond disk while increasing the clamping force to clamp the seconddisk, without increasing the size of the turntable, etc.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first-disk cartridge according toExample 1 of the invention, showing a condition in which the first-diskcartridge is not mounted in a recording/reproducing apparatus.

FIG. 2 is a perspective view of the first-disk cartridge according toExample 1, showing the condition in which the first-disk cartridge ismounted and positioned in a recording/reproducing apparatus.

FIG. 3 is a cross-sectional view of the first-disk cartridge of Example1 taken along line A-A' in FIG. 1.

FIG. 4 is a perspective view showing the external appearance of arecording/reproducing apparatus according to Example 1.

FIG. 5 is an enlarged cross-sectional view showing an essential portion(portion B in FIG. 3) of the first-disk cartridge mounted and positionedin the recording/reproducing apparatus, according to Example 1.

FIG. 6 is a perspective view showing the first-disk cartridge of Example1 ejected from the recording/reproducing apparatus.

FIG. 7 is a perspective view of a second-disk cartridge, with a tray ina retracted position, according to Example 1.

FIG. 8 is an exploded perspective view of a portion of the second-diskcartridge, with some parts broken away, according to Example 1.

FIG. 9 is a perspective view of a portion of the second-disk cartridge,with some parts broken away, according to Example 1.

FIG. 10 is a perspective view of a portion of the second-disk cartridge,with some parts broken away, according to Example 1.

FIG. 11 is a plan view of the second-disk cartridge, with the tray inretracted position and the upper half removed, according to Example 1.

FIG. 12 is a right side view of the second-disk cartridge, with the trayin retracted position, according to Example 1.

FIG. 13 is a rear view of the second-disk cartridge, with the tray inretracted position, according to Example 1.

FIG. 14 is a cross-sectional view of the second-disk cartridge ofExample 1 taken along line C-C' in FIG. 11.

FIG. 15 is an enlarged cross-sectional view of the second-disk cartridgeof Example 1 taken along line D-D' in FIG. 11.

FIG. 16 is an enlarged cross-sectional view of the second-disk cartridgeof Example 1 taken along line E-E' in FIG. 11.

FIG. 17 is an enlarged cross-sectional view taken along line F-F' inFIG. 11, showing a disk clamping device built into the second-diskcartridge according to Example 1.

FIG. 18 is a perspective view showing the second-disk cartridge ofExample 1 as viewed from a lower half side thereof, with the tray inretracted position.

FIG. 19 is an enlarged perspective view of a portion H in FIG. 18 of thesecond-disk cartridge of Example 1.

FIG. 20 is a perspective view of an unlocking unit, in deactivatedposition, built into the recording/reproducing apparatus according toExample 1.

FIG. 21 is a perspective view showing the second-disk cartridge, withthe tray in ejected position, according to Example 1.

FIG. 22 is a plan view of the second-disk cartridge, with the tray inejected position and the upper half removed, according to Example 1.

FIG. 23 is a cross-sectional view of the second-disk cartridge ofExample 1 taken along line G-G' in FIG. 22.

FIG. 24 is a perspective view showing the unlocking unit built into therecording/reproducing apparatus in activated position, according toExample 1.

FIG. 25 is an enlarged cross-sectional view taken substantially alongline F-F' in FIG. 11, showing the disk clamping device when thesecond-disk cartridge is mounted and positioned in therecording/reproducing apparatus, according to Example 1.

FIG. 26 is a perspective view showing the second-disk cartridge ejectedfrom the recording/reproducing apparatus, with the tray locked in aretracted position, according to Example 1.

FIG. 27 is a perspective view showing the second-disk cartridge ejectedfrom the recording/reproducing apparatus, with the tray in ejectedposition, according to Example 1.

FIG. 28 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing an essential portion(corresponding to portion B in FIG. 3) of a first-disk cartridge mountedand positioned in a recording/reproducing apparatus, according toExamples 2-5 of the invention.

FIG. 29 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with a trayin retracted position, according to Example 2 of the invention.

FIG. 30 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with a trayin retracted position, according to Example 3 of the invention.

FIG. 31 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with a trayin retracted position, according to Example 4 of the invention.

FIG. 32 is a perspective view showing a magnet and a magnetic member inExample 4.

FIG. 33A is a schematic diagram showing the action of the magnet andmagnetic member before clamping, according to Example 4.

FIG. 33B is a schematic diagram showing the magnetic flux from themagnet and magnetic member during clamping, according to Example 4.

FIG. 33C is a schematic diagram showing the magnetic flux from themagnet and magnetic member during clamping, according to Example 4, whenthe magnet and magnetic member are both magnetized in only onedirection.

FIG. 34 is a perspective view of a second-disk cartridge, with a tray inretracted position, according to Example 5 of the invention.

FIG. 35 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing the second-disk cartridgeof Example 5 mounted and positioned in a recording/reproducingapparatus, with the tray in retracted position.

FIG. 36 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing an essential portion(corresponding to portion B in FIG. 3) of a first-disk cartridge mountedand positioned in a recording/reproducing apparatus, according toExample 6 of the invention.

FIG. 37 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with a trayin retracted position, according to Example 6.

FIG. 38 is a perspective view showing a magnet and a magnetic member inExample 6.

FIG. 39 is a perspective view of a first-disk cartridge according toExample 7 of the invention, showing the condition in which thefirst-disk cartridge is not mounted in a recording/reproducingapparatus.

FIG. 40 is a perspective view showing a tray of a second-disk cartridgeaccording to Example 8 of the invention.

FIG. 41 is a perspective view showing a tray of a second-disk cartridgeaccording to Example 9 of the invention.

FIG. 42 is a perspective view of a first-disk cartridge mounted andpositioned in a recording/reproducing apparatus, according to Example10.

FIG. 43 is a perspective view showing a tray of a second-disk cartridgeaccording to Example 10 of the invention.

FIG. 44 is a perspective view showing a lower half (case) of thesecond-disk cartridge of Example 10.

FIG. 45 is a perspective view showing a tray of a second-disk cartridgeaccording to Example 11 of the invention.

FIG. 46 is a perspective view showing a lower half (case) of thesecond-disk cartridge of Example 11.

FIG. 47 is a perspective view showing a lower half (case) of asecond-disk cartridge according to Example 12 of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred examples of the present invention will be described belowwith reference to the accompanying drawings.

EXAMPLE 1

A disk cartridge and a disk clamping device according to Example 1 ofthe invention will be described with reference to FIGS. 1 to 27. Thepresent example concerns a construction that enables a second disk to bemounted and positioned in a recording/reproducing apparatus in which afirst-disk cartridge containing a first disk can be mounted andpositioned, and provides a second-disk cartridge which is as thin as afirst-disk cartridge and is capable of holding a second disk inremovable fashion.

(1) First-disk cartridge

FIGS. 1 and 2 show perspective views of the first-disk cartridge ofExample 1, and FIG. 3 shows a cross section of the same. As shown inFIGS. 2 and 3, a first disk 1 is contained in the first-disk cartridgeshown in FIG. 1. The following description deals with the constructionof the first disk 1 and of the first-disk cartridge.

First, the first disk 1 will be described. As shown in FIG. 3, the firstdisk 1 is a double-sided optical disk, about 120 mm in overall diameter,consisting of substrates 1a and 1b, each having a recording surface onthe side thereof facing inward, bonded together by UV adhesive or thelike. The substrates 1a and 1b are each formed from a colorless,transparent resin or glass. The thickness of the substrates 1a and 1bwhere the recording surfaces are formed is about 0.6 mm which is halfthe thickness (about 1.2 mm) of a second disk 51 that will be describelater. Mounting faces 1c and 1c', which are to be placed in contact witha turntable surface 32a (FIG. 5) of a turntable 32 in arecording/reproducing apparatus described later, are each formed in araised shape.

The first disk 1 has hubs 1d, 1d' at its center. The hubs 1d, 1d' aremade of magnetic stainless steel and bonded to the substrates 1a and 1b.First center holes 1e, 1e' are opened in the center of the respectivehubs 1d, 1d'. The first center holes 1e, 1e' have a diameter (about 3mm) slightly larger than that of a motor shaft 33 (FIG. 5) to bedescribed later. The first center holes 1e, 1e' therefore fitconcentrically onto the motor shaft 33 with good accuracy, and the firstdisk 1 is mounted onto the turntable 32 by the attraction of a magnet 34to be described later. The hubs 1d, 1d' are bonded, using a microscopeor the like, so that the first center holes 1e, 1e' are concentric withthe spiral-shaped or concentric information tracks formed on therecording surfaces of the substrates 1a, 1b. The construction is suchthat when the first disk 1 is mounted on the turntable 32, the motorshaft 33 contacts only one first center hole (the first center hole 1ein FIG. 5) that is nearer to the turntable 32.

Next, the first-disk cartridge will be described. As shown in FIG. 1,the first-disk cartridge includes a first casing 2. The first casing 2has a first opening hole 2d, as shown in FIGS. 2 and 5. The first-diskcartridge has a first shutter 8 for opening and closing the firstopening hole 2d, as shown in FIGS. 1 and 2. A shutter open/close member13, connected to the first shutter 8, is operated to open and close thefirst shutter 8. When the first-disk cartridge is not mounted in therecording/reproducing apparatus, the first shutter 8 is locked in theclosed position by means of a shutter locking member 15.

The depth x1, the width y1 and the height z1 of the first-disk cartridgeare about 133 mm, about 124 mm and about 8 mm, respectively.

Each component part of the thus constructed first-disk cartridge will bedescribed in detail below.

First, the construction of the first casing 2 will be described. Thefirst casing 2 consists of an upper half 2a and lower half 2b formedfrom ABS resin. The upper half 2a and lower half 2b are joined togetherby screws or by heat welding. Inside the first casing 2 is formed afirst-disk holding recess 2c capable of holding the first-disk 1, asshown in FIG. 3. When not in use, the first disk 1 is supported onprotrusions 2h formed at positions corresponding to the non-data areasaround the inner and outer circumferences of the first disk 1. Thediameter of the first-disk holding recess 2c is made slightly largerthan the outer diameter of the first disk 1, and is set, for example, atabout 122 mm. The first opening hole 2d allows the insertiontherethrough the turntable 32 and head provided in therecording/reproducing apparatus, as will be described later.

In the upper half 2a and lower half 2b, there are formed a pair of firstpositioning holes 2f that act as first positioning means, as shown inFIGS. 1 and 2 (the positioning holes in the lower half 2b are notshown). One of the first positioning holes 2f is a round hole, while theother is an elongated hole, in compliance with a known positioningtechnique. The first positioning holes 2f enable the first casing 2 tobe positioned in place when the first-disk cartridge is inserted intothe recording/reproducing apparatus.

Furthermore, recesses 2j are formed in respective end portions of +Y and-Y sides of the first casing 2, as shown in FIGS. 1 and 2. Engaging withthese recesses 2j, levers (not shown) provided on +Y and -Y sides in therecording/reproducing apparatus are moved in X directions to drive thefirst shutter locking member 15 and first shutter open/close member 13.

The first-disk cartridge may be constructed to have positioning recesses2g, as shown in FIGS. 1 and 2. This construction enables the first-diskcartridge to be chucked by an automatic loading device, allowing the usewith a so-called stocker type recording/reproducing apparatus. A stockertype recording/reproducing apparatus is a recording/reproducingapparatus of the type in which a plurality of first-disk cartridges areaccommodated, each disk cartridge being automatically mounted andejected. Each of the recesses 2j is provided with a semi-circularpositioning recess 2i. These positioning recesses 2i enable thefirst-disk cartridge to be chucked when inserted into therecording/reproducing apparatus.

Further, the upper half 2a and lower half 2b are each provided with arecess 2q in which the first shutter 8 is mounted slidably along Ydirections, as shown in FIG. 1.

Next, the first shutter 8 and its associated parts will be describedbelow. As shown in FIG. 1, when the first-disk cartridge is not mountedin the recording/reproducing apparatus, i.e., when the first-diskcartridge is not in use, the first shutter 8 is set in the closedposition by a spring or the like (not shown) to close the first openinghole 2d. The first shutter 8 is secured to a first-shutter guide 9 byscrews or other means, and is mounted in the first casing 2 slidablyalong Y directions. For the first shutter guide 9, a material such as apolyacetal resin is preferable; more specifically, a resin that has asmall sliding resistance and high wear and chafing resistance againstthe mating resin (in this example, the first casing 2 made of ABS resin)is desirable.

The first shutter 8 is connected to the first-shutter open/close member13 by a belt or the like (not shown). A first-shutter holder 14 is fixedby adhesion or other means to the positioning recess 2q in the firstcasing 2, as shown in FIGS. 1 and 2. The first-shutter holder 14 holdsone end of the first shutter 8 against the recess 2q in the first casing2, as shown in FIG. 5, to prevent the end of the first shutter 8 fromlifting in Z direction.

The first-shutter locking member 15 is movable in Y directions, as shownin FIGS. 1 and 2, and is urged toward the +Y side by a spring or thelike (not shown) so as to protrude into the recess 2j. In thiscondition, the first-shutter locking member 15 engages with an engagingportion (not shown) of the first-shutter guide 9. The first-shutterlocking member 15 thus locks the first shutter 8 in position.

The first disk 1 can be mounted on the turntable 32 whether thefirst-disk cartridge is inserted with the substrate 1a (i.e., the lowerhalf 2b) facing the turntable 32 or with the substrate 1b (i.e., theupper half 2a) facing the turntable 32.

FIG. 4 is a perspective view showing a portion of therecording/reproducing apparatus in which the first-disk cartridge isused, and FIG. 5 is a cross-sectional view showing the first-diskcartridge mounted and positioned in the recording/reproducing apparatus.The recording/reproducing apparatus will be described below withreference to FIGS. 4 and 5.

As shown in FIG. 4, an outer housing 31 of the recording/reproducingapparatus has an insertion slot 31a in the front thereof (on the -Xside), through which the first-disk cartridge or the second-diskcartridge hereinafter described can be inserted. Therecording/reproducing apparatus has two eject buttons 31b and 31c. Theeject button 31b is used to eject the first-disk cartridge or eject thesecond-disk cartridge with its second casing locked in retractedposition. The eject button 31c is used to eject the second-diskcartridge with its second casing in extended position. The second-diskcartridge is thus capable of being set in one of two positions, with thesecond casing in retracted position or in extended position. Thisoperation will be described in detail later.

In this example, the tray eject button 31c is provided in addition tothe usual eject button 31b so that the second-disk cartridge can beejected with the casing either in retracted position or in extendedposition as desired. Another method may be used. For example, it may beso constructed that using only one eject button 31, the cartridge isejected with the casing in retracted position when the button is pressedonly once, and ejected with the casing in extended position when thebutton is pressed two or more times.

The recording/reproducing apparatus contains therein the turntable 32,motor shaft 33, and magnet 34 shown in FIG. 5. The turntable 32 is fixedintegrally to the motor shaft 33. The turntable 32 is driven to rotatethe first disk 1 or the hereinafter described second disk 51 mounted onthe turntable surface 32a. The motor shaft 33 has a diameter of about 3mm, and fits in the first center hole 1e, 1e' of the hub 1d, 1d' of thefirst disk 1 as well as in a center hole 64a opened through a magneticmember 64 of the second disk 51 to be described later. The magnet 34 isa cylindrically shaped magnet fixed to the turntable 32. The magnet 34is, for example, divided into four regions 90 degrees apart andmagnetized alternately in +Z and -Z directions (i.e., four poles).

The recording/reproducing apparatus further includes a head (not shown)movable in X directions for information recording and reproduction forboth the first disk 1 and the second disk 51 whose substrates havedifferent thickness from each other.

The following describes how the thus constructed first-disk cartridge isused with the recording/reproducing apparatus.

First, the operation for loading the first-disk cartridge into therecording/reproducing apparatus will be described.

When the first-disk cartridge, with its -X side held by hand, isinserted in the insertion slot 31a provided in the outer housing 31 ofthe recording/reproducing apparatus, the positioning recesses 2i formedin the first casing 2 are chucked by holder pins (not shown) of aloading mechanism provided in the recording/reproducing apparatus, andthe first-disk cartridge is guided in the +X direction.

As the first casing 2 is moved in the +X direction, the first-shutterlocking member 15 is pushed toward the -Y side by a lever (not shown)provided on the +Y side in the recording/reproducing apparatus, and thelock is released. At the same time, the first-shutter open/close member13 is engaged by a lever (not shown) provided on the -Y side in therecording/reproducing apparatus; as the first casing 2 is moved in the+X direction, the first-shutter open/close member 13 is pushed in the -Xdirection relative to the first casing 2, as can be seen from FIGS. 1and 2. As a result, the first shutter 8 is moved in the -Y direction tofully open the first opening hole 2d.

After that, the first-disk cartridge is moved in the -Z direction by theloading mechanism, and using the first positioning holes 2f (not shown)on the -Z side (in the lower half 2b), the first casing 2 is accuratelypositioned with positioning pins or the like in therecording/reproducing apparatus. At the same time, the turntable 32,etc. of the recording/reproducing apparatus are inserted through thefirst opening hole 2d, and the first center hole 1e mof the hub 1dengages on the motor shaft 33, as shown in FIG. 5. As a result, themounting face 1c is made to contact with the turntable surface 32a;thus, the first disk 1 is mounted on the turntable 32 concentricallywith the motor shaft 33. Further, a head (not shown) is inserted fromthe -Z side of the first opening hole 2d. With the above operation, thefirst disk 1 is now set ready for information recording, reproduction,or erasure.

Next, the operation for ejecting the first-disk cartridge from therecording/reproducing apparatus will be described below. FIG. 6 is aperspective view showing the first-disk cartridge ejected from therecording/reproducing apparatus.

When the eject button 31b on the recording/reproducing apparatus ispushed by a finger, the first-disk cartridge is moved by the loadingmechanism in the +Z direction, disengaging the first casing 2 from theposition set by the first positioning holes 2f on the -Z side. At thesame time, the turntable 32, etc. of the recording/reproducing apparatusare disengaged from the first opening hole 2d.

Then, the first-disk cartridge is ejected through the same path that itwas loaded, but in the reverse direction. In the ejecting process, thepositioning recesses 2i of the first casing 2 are unchucked, and thelever on the recording/reproducing apparatus side is disengaged from thefirst-shutter open/close member 13. As a result, the first-shutter 8 ismoved in the +Y direction by the restoring force of a spring or the liketo fully close the first opening hole 2d, while at the same time, thefirst shutter open/close member 13 is moved in the +X direction. At thesame time, the first-shutter locking member 15 engages with the engagingportion of the first-shutter guide 9, thus locking the first shutter 8in position.

As a result, the first-disk cartridge is guided in the -X direction, andejected through the insertion slot 31a, as shown in FIG. 6. Thedimension a1 by which the first-disk cartridge is ejected in the -Xdirection is chosen to be about 50 mm.

In the condition shown in FIG. 6, the first-disk cartridge can beremoved from the recording/reproducing apparatus by holding the -X sideof the cartridge.

(2) Second-disk cartridge

FIG. 7 shows a perspective view of a second-disk cartridge according tothe present example, and FIGS. 8 to 10 show perspective views of thesecond-disk cartridge with some parts broken away for clarity. As shown,a second disk 51 is loaded in the second-disk cartridge. Theconstruction and operation of the second disk 51, the second-diskcartridge, and the disk clamping device built into the second-diskcartridge will be described below.

First, the second disk 51 will be described. The second disk 51 is asingle-sided optical disk having an overall diameter of about 120 mm,which is the same as that of the first disk 1, and consisting of asingle substrate having a recording surface on the +Z side in thefigure. A second center hole 51a, about 15 mm in diameter, is formed inthe center of the second disk 51, as shown in FIG. 8. The substrateforming the second disk 51 is made of colorless, transparent resin orglass, and has a thickness of about 1.2 mm. The second center hole 51ais formed by molding, for example, such that it is concentric with thespiral-shaped track or concentric tracks formed on the recordingsurface.

Next, the second-disk cartridge will be described. As shown in FIG. 7,etc., the second-disk cartridge includes a case 52 and a tray 53. Thecase 52 and tray 53 together constitute a second casing that forms theouter shape of the second-disk cartridge. The outer dimensions of thesecond-disk cartridge, i.e., the depth x2, the width y2, and the heightz2, are the same as the corresponding dimensions of the first-diskcartridge; that is, the depth x2 is about 133 mm, the width y2 about 124mm, and the height z2 about 8 mm.

In this specification, "the extended position of the second casing"indicates the condition in which the tray 53 is ejected from the case52, as shown in FIGS. 21 to 23, while "the retracted position of thesecond casing" indicates the condition in which the tray 53 is drawninside the case 52, as shown in FIG. 7. A belt 54 and a spring 55, shownin FIG. 9, constitute means for driving the second casing from theretracted position to the extended position.

Each component part of the thus constructed second-disk cartridge willbe described in detail below.

First, the construction of the second casing will be described. The case52 consists of an upper half 52a and lower half 52b formed from ABSresin. The upper half 52a and lower half 52b are joined together attheir ends, forming an integral construction inside of which is formed atray holding recess 52c, as shown in FIG. 23. The tray 53 is housedmovably inside the tray holding recess 52c. The upper half 52a and lowerhalf 52b may be secured together by screws 61 shown in FIG. 8 which arescrewed through screw holes 52r in the upper half 52a shown in FIG. 8and screw holes 52n in the lower half 52b shown in FIG. 10.Alternatively, they may be joined together by heat welding.

The upper half 52a has an arc-shaped notch 52e on its -X side, as shownin FIGS. 7 and 8. The notch 52e has a diameter of about 124 mm which isslightly larger than the outer diameter (about 120 mm) of the first disk1 or second disk 51.

As shown in FIG. 10, the lower half 52b has a second sub-opening hole(hereinafter called the second opening hole, for simplicity) 52d in theposition corresponding to the position of the first opening hole 2dformed in the first-disk cartridge. The second sub-opening hole 52d ismade slightly larger than a second opening hole (hereinafter called thesecond opening hole, for simplicity) 53d, to be described later, formedin the tray 53, and allows the turntable 32 and head provided in therecording/reproducing apparatus to be inserted therethrough.

As shown in FIG. 10, the lower half 52b further includes a pair ofsecond positioning holes 52f that act as second positioning means. Thesecond positioning holes 52f are formed in the positions correspondingto the positions of the first positioning holes 2f formed in thefirst-disk cartridge, and are made slightly larger than secondpositioning holes 53f, to be described later, formed as secondpositioning means in the tray 53. One of the second positioning holes52f is a round hole, and the other is an elongated hole, as practiced bya known positioning technique. The second positioning holes 52f serve toset the second casing 52 in position when the second-disk cartridge isinserted into the recording/reproducing apparatus. The lower half 52balso has a hole 52k to permit the protrusion 53o of the tray 53, to bedescribed later, to move in X directions. The second positioning hole52f on the -Y side is formed continuously with the hole 52k.

Furthermore, recesses 52j are formed in respective end portions of +Yand -Y sides of the case 52, as shown in FIGS. 7, 10, and 12. Therecesses 52j are formed in the positions corresponding to the positionsof the recesses 2j formed in the first-disk cartridge, and havecorresponding shapes. These recesses 52j serve to avoid the levers (notshown) that are provided on the +Y and -Y sides in therecording/reproducing apparatus to drive the first-shutter lockingmember 15 and first-shutter open/close member 13 of the first-diskcartridge. Inside the recesses 52j of the case 52 are formedsemi-circular positioning recesses 52i in the positions corresponding tothe positions of the positioning recesses 2i formed in the first-diskcartridge, the recesses 52i being similar in shape to the recesses 2i.The provision of the positioning recesses 52i enables the second-diskcartridge to be chucked when the second-disk cartridge is inserted intothe recording/reproducing apparatus.

The tray 53, together with the upper half 52a and lower half 52b formingthe case 52, constitutes the second casing. The tray 53 has on its -Zside a pair of parallel protrusions (not shown) extending in an Xdirection which fit in a pair of parallel recesses 521 formed in thelower half 52b shown in FIG. 10. The tray 53 is thus made free to movein X directions relative to the case 52. The movement of the tray 53 inY directions is restricted by the -Y side protrusion of the tray 53fitted into the -Y side recess 521 of the lower half 52b, while the +Yside recess 521 is formed to leave a clearance in Y directions when the-Y side protrusion is fitted. That is, the movement of the tray 53 in Ydirections is limited only by the -Y side recess 521 and its matingprotrusion. As for the restriction of movements in Z directions, thebottom faces of the protrusions and recesses 521 serve to limit themovement of the tray 53 in the -Z direction, while the movement of thetray 53 in the +Z direction is limited by the upper faces of protrusions53m and the inner surface (not shown) of the upper half 52a. For thetray 53, especially the sliding portions thereof, a material such as apolyacetal resin is preferable; more specifically, a resin that has asmall sliding resistance and high wear and chafing resistance againstthe mating resin (in this example, the case 52 made of ABS resin) isdesirable.

Inside the tray 53 is formed a second-disk holding recess 53c capable ofholding a second disk 51, as shown in FIG. 9. When not in use, thesecond disk 51 is supported on protrusions 53h formed at positionscorresponding to the non-data areas around the inner and outercircumferences of the second disk 51. As in the case of the first-diskholding recess 2c, the second-disk holding recess 53c has a diameter ofabout 122 mm, for example, which is slightly larger than the outerdiameter of the second disk 51. When the second casing is in theretracted position, the center position of the second-disk holdingrecess 53c is substantially coincident with the corresponding positionof the first-disk holding recess 2c.

The tray 53 has a second opening hole 53d, as shown in FIG. 9. Thesecond opening hole 53d corresponds in position and shape to the firstopening hole 2d formed in the first-disk cartridge. The second openinghole 53d allows the turntable 32 and head provided in therecording/reproducing apparatus to be inserted therethrough.

The tray 53 has a pair of second positioning holes 53f that act assecond positioning means. The second positioning holes 53f correspond inposition and shape to the positioning holes 52f formed in the lower half52b. That is, one of the second positioning holes 53f is a round hole,and the other an elongated hole. These positioning holes 53f enable thetray 53 to be set in position when the second-disk cartridge is insertedinto the recording/reproducing apparatus.

When the second casing is in the extended position, an end face 53p(FIG. 16) of the protrusion 53o is engaged with an end face 52w of thehole 52k formed in the lower half 52b shown in FIG. 10, thereby limitingthe further movement of the tray 53. The X-direction stroke that thetray 53 travels from the retracted position to the ejected position ischosen to be about 80 mm.

Next, the belt 54 will be described. FIG. 11 is a plan view showing thetray 53 loaded into the case 52 with the upper half 52a removed forclarity. As shown in FIG. 11, the belt 54 is guided along a side face53e of the tray 53, and is fixed at one end to the spring 55 and at theother to the case 52. The case 52 and the tray 53 are thus connected viathe spring 55. The spring 55 is a tension spring. As shown in FIG. 9 inwhich component parts are broken away for clarity, one end 55a of thespring 55 is passed through a hole 54a of the belt 54, and the other end55b is hooked on a spring hook 53i formed on the tray 53. The spring 55urges the tray 53 in the -X direction relative to the case 52 via thebelt 54. That is, using its restoring force, the spring 55 acts to movethe tray 53 from the retracted position shown in FIG. 7 (the retractedposition of the second casing) to the ejected position shown in FIGS. 21to 23 (the extended position of the second casing). Since the belt 54and spring 55 are installed along the +X and -Y side faces of the tray53 in such a manner as to overlap the locus of the moving tray 53, theprovision of the belt 54 and spring 55 does not involve an increase inthe height of the second-disk cartridge. Pins 56, shown in FIG. 9, whichare used to retain the belt 54 to the case 52, are inserted throughholes 54b formed in the belt 54, and secured by adhesion or other meansto positioning recesses 52m formed in the case 52 shown in FIG. 10. Thepins 56 may be formed integral with the belt 54 by molding or othertechnique.

Other components parts forming the second-disk cartridge will bedescribed below.

Description will be given below of a damper 57 provided to smoothen themovement of the tray 53 in X directions relative to the case 52. FIG. 16is an enlarged cross-sectional view taken along line E-E' in FIG. 11,showing the damper 57 and its adjacent parts. The damper 57 includes apinion 57a, a shaft 57c, a damping plate 57d, a fluid 57e, and a base57f through which holes 57b are opened (see the damper 57 broken awayfrom the second-disk cartridge shown in FIG. 9). The shaft 57c to whichthe pinion 57a is fixed is supported rotatably on the base 57f. Thefluid 57e such as silicone oil is filled inside the base 57f in such amanner as to surround the disc-shaped damping plate 57d fixed to theshaft 57c. The damper 57 is fixed in place by adhesion or other meanswith its holes 57b engaging on the pins 531 formed in the recess 53k(FIG. 9) of the tray 53. The pinion 57a of the damper 57 engages withthe rack 52u (also see FIG. 8) formed on the upper half 52a.

Next, a locking unit for locking the tray 53 in the case 52 into theretracted position shown in FIG. 7 will be described. The locking unitconsists of a locking pawl 58, a spring 59, and retaining plates 60, asshown in FIG. 10. FIG. 15 is an enlarged cross-sectional view takenalong line D-D' in FIG. 11, showing the locking unit in locked positionand its adjacent parts. FIG. 19 is an enlarged view of portion H showingthe locking unit in FIG. 18 that shows a perspective view of thesecond-disk cartridge as viewed from the lower half 52b side.

The locking pawl 58 consists of a first shaft 58a, a second shaft 58b(FIG. 15), and a lock release 58c, as shown in FIG. 10. The lock release58c is inserted in a hole 52q formed in the lower half 52b, while theshaft 58a is inserted in between guide portions 52p formed on the lowerhalf 52b and rotatably supported thereon. Using the thus constructedlocking unit, the tray 53 is locked into the retracted position in thecase 52. The end of the lock release 58c protrudes on the lower half 52bside as shown in FIG. 19. An end face 58e of the locking pawl 58 engageswith an end face 53w of a locking portion 53j on the tray 53, toaccomplish the locking condition shown in FIG. 15. The lock release 58cis exposed in a slit-like recess 52v formed in the -Z side of the lowerhalf 52b, as shown in FIG. 13.

The spring 59 is a compression spring, as shown in FIG. 15, one end 59a(FIG. 10) of which is fitted onto a shaft 52o formed on the lower half52b; the other end 59b (FIG. 10) is fitted onto the shaft 58b of thelocking pawl 58. In this arrangement, the spring 59 urges the shaft 58bof the locking pawl 58 in the +Z direction at all times.

With the shaft 58a of the locking pawl 58 inserted in between the guideportions 52p of the lower half 52b, the retaining plates 60 are fixed tothe upper faces of the guide portions 52p by adhesion or other means.This limits the movement of the shaft 58a of the locking pawl 58 in the+Z direction.

Next, the construction of the disk clamping device built into thesecond-disk cartridge will be described. FIG. 17 shows a cross sectionof the disk clamping device taken along line F-F' in FIG. 11. The diskclamping device consists of a clamp base 62, an elastic member 63, amagnetic member 64, and a clamp supporting plate 65, as shown in brokenaway form in FIG. 8.

The clamp base 62 includes a centering part 62d that can fit into thesecond center hole 51a of the second disk 51. The clamp base 62 is fixedto the clamp supporting plate 65, with a cylindrical portion 62binserted in a hole 52t formed in the upper half 52a (also see FIG. 8).The clamp base 62 and the clamp supporting plate 65 may be joinedtogether by screwing flush head screws 66 through screw holes 62a in theclamp base 62 and screw holes 65a in the clamp supporting plate 65, asshown in FIG. 8, or may be bonded together by adhesion or other means.The clamp supporting plate 65 is inserted in an arc-shaped recess 52s(also see FIG. 8) formed in the upper half 52a, and supports the clampbase 62, etc. in rotatable fashion.

The elastic member 63 is a disc-shaped sponge, which is, as shown inFIG. 17, fixed to a mounting face 62c of the clamp base 62. Any elasticmaterial, such as rubber, for example, may be used to form the elasticmember 63.

Like the hubs 1d, 1d' of the first disk 1, the magnetic member 64 isformed from a magnetic stainless steel. The center hole 64a openedthrough the magnetic member 64 shown in FIG. 17 has a slightly largerdiameter (about 3 mm) than that of the motor shaft 33. The center hole64a therefore fits concentrically onto the motor shaft 33 with goodaccuracy, to clamp the second disk 51 against the turntable 32 by beingattracted by the magnet 34. Using a microscope or the like, the magneticmember 64 is fixed to the clamp base 62 by adhesion or other means withthe center hole 64a aligned concentrically with the centering part 62d.As described, the centering unit consists of the clamp base 62, elasticmember 63, centering part 62d, and center hole 64a.

The second-disk cartridge is constructed so that the second disk 51 canbe mounted on the turntable 32 only when the second-disk cartridge isinserted in the recording/reproducing apparatus with the lower half 52dfacing the turntable 32.

The recording/reproducing apparatus shown in FIG. 4 has an unlockingunit for releasing the locking unit of the second-disk cartridge. Theunlocking unit of the recording/reproducing apparatus will be describedbelow. FIGS. 20 and 24 show perspective views of the unlocking unit. Theunlocking unit consists of a solenoid 101, a spring 102, a connectingplate 103, a swing pin 104, a release pin 105, and an energizing circuit106.

The solenoid 101 consists essentially of a body 101a containing anelectromagnet, and an iron core 101b supported movably in X directionsrelative to the body 101a. The spring 102 is fitted on the iron core101b to push the connecting plate 103 in the -X direction. Theconnecting plate 103 is supported swingably on the swing pin 104 fixedto the body (not shown) of the recording/reproducing apparatus. Theconnecting plate 103 has elongated holes 103a and 103b at both endsthereof. The iron core 101b of the solenoid 101 is connected to theconnecting plate 103, with a pin, formed at the end of the iron core101b, inserted through the elongated hole 103a. On the other hand, theelongated hole 103b is used to connect the connecting plate 103 with therelease pin 105.

The release pin 105 is supported in the body of therecording/reproducing apparatus in such a manner as to be movable in Xdirections only. The release pin 105 has a slit 105a, and is connectedto the connecting plate 103 with a pin, formed in the slit 105, insertedin the elongated hole 103b. The release pin 105 has an unlocking pin105b at its tip, as shown in FIG. 20; the unlocking pin 105b is guidedalong the slit-like recess 52v to push the lock release 58c of thelocking pawl 58.

The energizing circuit 106 is connected to the solenoid 101 to controlthe energization/deenergization of the solenoid 101. When the activationof the tray eject button 31c (FIG. 4) is detected by a detecting circuit107, an energization command is sent to the energizing circuit 106.

The operation of the thus constructed unlocking unit will be describedbelow.

When the tray eject button 31c is in the deactivated state, thedetecting circuit 107 does not send an energization command to theenergizing circuit 106, so that the energizing circuit 106 is off.Therefore, the solenoid 101 is not energized. As a result, as shown inFIG. 20, the elongated hole 103a end of the connecting plate 103 is inits extreme -X position because of the restoring force of the spring102, which means that the elongated hole 103b end thereof is in itsextreme +X position. This further indicates that the release pin 105 isalso in its extreme +X position, and therefore, is separated from thelock release 58c of the locking pawl 58 on the second-disk cartridge.

When the tray eject button 31c is pressed, the detecting circuit 107sends an energization command to the energizing circuit 106, so that theenergizing circuit 106 is turned on to energize the solenoid 101. As aresult, the iron core 101b is pulled in the +X direction, as shown inFIG. 24. This causes the connecting plate 103 to turn about the swingpin 104 against the restoring force of the spring 102. As a result, theelongated hole 103a end moves in the +X direction, and the elongatedhole 103b end in the -X direction. With this movement of the connectingplate 103, the release pin 105 is moved in the -X direction, until thetip of the unlocking pin 105b pushes the lock release 58c of the lockingpawl 58 on the second-disk cartridge and thus releases the lock.

The operation of the thus constructed second-disk cartridge andrecording/reproducing apparatus will be described below.

First, description will be given of the operation performed wheninserting the second-disk cartridge into the recording/reproducingapparatus.

When the second disk 51 is loaded in the second-disk cartridge and thetray 53 is in the retracted position as shown in FIG. 7, the second-diskcartridge can be inserted as-is into the recording/reproducingapparatus. On the other hand, when the second-disk cartridge is not yetloaded with the second disk 51, the second disk 51 may be loaded intothe second-disk cartridge either before or after the second-diskcartridge is inserted in the recording/reproducing apparatus.

First, the description is given of the operation for the case in whichthe second disk 51 is loaded into the second-disk cartridge before thesecond-disk cartridge is inserted into the recording/reproducingapparatus.

If, in FIG. 7, the second-disk cartridge is not yet loaded with thesecond disk 51, the tray 53 is unlocked first. Unlocking the tray 53 canbe accomplished by pressing by a finger, etc. the lock release 58c ofthe locking pawl 58, exposed through the hole 52q in the lower half 52b,as shown in FIGS. 13 and 19. This causes the end face 58e of the lockingpawl 58 to move down in the -Z direction against the restoring force ofthe spring 59 of the locking unit; the end face 58e is then disengagedfrom the end face 53w of the locking portion 53j on the tray 53 (seeFIG. 15), thus unlocking the tray 53. As a result, the tray 53 is movedabout 80 mm in the -X direction relative to the case 52 by the restoringforce of the spring 55. That is, the tray 53 is moved from the retractedposition shown in FIG. 11 to the ejected position shown in FIG. 22.Since the movement of the tray 53 is regulated by the damper 57, thetray 53 moves slowly so that there is no danger of injury if the usertouches the tray 53 in motion.

Next, the second disk 51 is held by hand, and placed onto thesecond-disk holding recess 53c (FIG. 9) in the tray 53. Then, the tray53 is manually moved in the X direction into the case 52 against therestoring force of the spring 55. As the tray 53 moves, the spring 55gradually stretches, until the locking portion 53j of the tray 53 hitsthe lock pawl 58. After that, with the tapered face 53n of the tray 53pushing the tapered face 58d of the locking pawl 58 in the +X direction,the locking pawl 58 is turned against the restoring force of the spring55 so that the end face 58e moves down in the -Z direction. In thissituation, when the tray 53 moves further in the +X direction, thelocking portion 53j of the tray 53 overrides the +Z side end face of thelocking pawl 58. At the same time, the end face 58e of the locking pawl58 is turned in the +Z direction by the restoring force of the spring55, and is engaged with the end face 53w of the tray 53 (FIG. 9). Thetray 53 is thus locked in the case 52, as shown in FIG. 15,accomplishing the condition shown in FIG. 7 in which the second-diskcartridge is loaded with the second disk 51 and the tray 53 is inretracted position.

An alternative way of loading the tray 53 into the case 52 is by firstinserting the case 52 in the insertion slot 31a of therecording/reproducing apparatus, with the second disk 51 placed on thesecond-disk holding recess 53c as shown in FIG. 21, and then pushing thetray 53 into the +X direction.

Returning to the condition shown in FIG. 7, the second-disk cartridgecontaining the second disk 51 is held by the -X side, as with thefirst-disk cartridge, and is inserted in the insertion slot 31a formedin the outer housing 31 of the recording/reproducing apparatus; then,the positioning recesses 52i formed in the case 52 are chucked by holderpins (not shown) of the loading mechanism in the recording/reproducingapparatus, and the second-disk cartridge is guided in the +X direction.

At this time, the recesses 52j formed in the case 52 serve to preventthe levers (not shown) provided on the +Y and -Y sides in therecording/reproducing apparatus from interfering with the mechanism ofthe case 52 while the case 52 is being drawn in the +X direction.

Further, as with the first-disk cartridge, the second-disk cartridge ismoved in the -Z direction by the action of the loading mechanism, andset in the specified position with the second positioning holes 52f and53f; in particular, the tray 53 is accurately positioned with thepositioning pins or the like (not shown) in the recording/reproducingapparatus fitting through the second positioning holes 52f in the lowerhalf 52b and through the second positioning holes 53f in the tray 53(see FIG. 18). The second positioning holes 52f formed in the lower half52b are made larger than the second positioning holes 53f in the tray53, since the case 52 needs to be positioned accurately in Z directionsonly, while the tray 53 with the second disk 51 directly held thereonneeds to be positioned accurately in both X and Y directions.

At the same time, the disk clamping device is put into action. That is,as shown in FIG. 25, the turntable 32, etc. of the recording/reproducingapparatus are inserted through the second opening hole 52d (FIG. 10) inthe lower half 52b and through the second opening hole 53d (FIG. 9) inthe tray 53, and the second disk 51 is mounted on the turntable surface32a. After that, the second center hole 51a of the second disk 51 isguided concentrically with the centering part 62d of the clamp base 62,and the center hole 64a of the magnetic member 64 engages onto the motorshaft 33. At this time, the elastic member 63 is pressed in the Zdirection, and the second center hole 51a is brought into contact withthe centering part 62d. In this situation, the magnetic member 64 isattracted by the magnet 34 to clamp the second disk 51 in position. Thatis, the second disk 51 is held in the clamped position while holding thecenter hole 51a, and hence the information track, in concentricrelationship with the motor shaft 33.

Further, a head (not shown) is inserted from the -Z side through thesecond opening holes 52d and 53d. With the above sequence of operations,the disk is set ready for information recording, reproduction, orerasure.

Next, description is given of the operation performed when ejecting thesecond-disk cartridge from the recording/reproducing apparatus.

There are two methods of ejecting the second-disk cartridge from therecording/reproducing apparatus: One is by pressing the eject button31b, and the other is by pressing the tray eject button 31c (see FIG.4).

First, the method of ejecting the second-disk cartridge by pressing theeject button 31b will be described. This ejection method is particularlyuseful when replacing the second-disk cartridge with the first-diskcartridge or with another second-disk cartridge.

When the eject button 31b on the recording/reproducing apparatus ispressed by a finger, the second-disk cartridge is moved in the +Zdirection by the action of the loading mechanism, disengaging the case52 and tray 53 from the position set by the second positioning holes 52fand 53f. At the same time, the turntable 32, head, etc. of therecording/reproducing apparatus are disengaged from the second openinghole 52d in the lower half 52b and the second opening hole 53d in thetray 53.

Then, the second-disk cartridge is ejected through the same path that itwas loaded, but in the reverse direction. That is, as with thefirst-disk cartridge, the second-disk cartridge is guided in the -Xdirection, and ejected through the insertion slot 31a, as shown in FIG.26. The dimension a2 by which the second-disk cartridge is ejected inthe -X direction is, of course, chosen to be about 50 mm, as with thefirst-disk cartridge.

In the condition shown in FIG. 26, the second-disk cartridge can beremoved from the recording/reproducing apparatus by holding the -X sideof the cartridge.

Next, the method of ejecting the second-disk cartridge by pressing thetray eject button 31c will be described. This ejection method isparticularly useful when replacing the second disk 51 mounted on thetray 53 with another second disk 51.

First, when the tray eject button 31c on the recording/reproducingapparatus is pressed by a finger, the second-disk cartridge is moved inthe +Z direction by the action of the loading mechanism, disengaging thecase 52 and tray 53 from the position set by the second positioningholes 52f and 53f. At the same time, the turntable 32, head, etc. of therecording/reproducing apparatus are disengaged from the second openingholes 52d and 53d.

After that, the unlocking pin 105b of the release pin 105 forming partof the unlocking unit provided in the -Z side of therecording/reproducing apparatus is extended to push the lock release 58cof the locking pawl 58 exposed through the hole 52q in the lower half52, as previously described. This causes the end face 58e of the lockingpawl 58 to move down in the -Z direction against the restoring force ofthe spring 59, and the end face 58e is disengaged from the end face 53wof the locking portion 53j, thus unlocking the tray 53.

When unlocked, the tray 53 is moved about 80 mm in the -X directionrelative to the case 52 by the restoring force of the spring 55. Sincethis movement of the tray 53 is regulated by the damper 57, the tray 53moves slowly.

Then, the second-disk cartridge is ejected through the same path that itwas loaded, but in the reverse direction. That is, as with thefirst-disk cartridge, the second-disk cartridge is guided in the -Xdirection, and ejected through the insertion slot 31a, as shown in FIG.27. The dimension a3 by which the tray 53 of the second-disk cartridgeis ejected in the -X direction is about 130 mm, i.e. the sum of theejection dimension, about 80 mm, of the tray 53 ejected from the case 52and the ejection dimension, about 50 mm, of the case 52 itself.

In the condition shown in FIG. 27, the second disk 51 mounted on thedisk holding recess 53c of the tray 53 can be removed for mounting ofanother second disk 51. Otherwise, the second-disk cartridge can beremoved from the recording/reproducing apparatus by holding the -X sideof the tray 53.

Further, in the condition shown in FIG. 27, the tray 53 may be pushed inthe +X direction, with the second disk 51 removed or left on it, thusleaving the second-disk cartridge loaded in the recording/reproducingapparatus when not in use. In this case, when it becomes necessary touse the recording/reproducing apparatus for recording or reproduction ofanother second disk 51, the tray eject button 31c is pressed in the samemanner as described above; since the tray 53 is ejected as shown in FIG.27, the desired second disk 51 can be mounted on the second-disk holdingrecess 53c for use.

The constructions and advantageous effects of the present example can besummarized as follows:

(a) The telescopic structure of the second casing consisting of the case52 and tray 53 permits the loading and unloading of the second disk 51as desired. Further, when the second casing is locked in the retractedposition, the second positioning holes 52f, 53f (second positioningmeans) substantially coincide in position and shape with the firstpositioning holes 2f (first positioning means) formed in the first-diskcartridge, and the second opening holes 52d, 53d substantially coincidein position and shape with the first opening hole 2d formed in thefirst-disk cartridge or are larger than the first opening hole 2d so asto include the entire area corresponding to the first opening hole 2d;this structure permits the use of the second-disk cartridge in arecording/reproducing apparatus designed for use with the first-diskcartridge. As a result, the recording/reproducing apparatus need nothave two loading mechanisms. Thus, it is possible to provide asecond-disk cartridge which enables a second disk 51 to be mounted andpositioned in a recording/reproducing apparatus capable of mounting andpositioning therein a first-disk cartridge containing a first disk 1,and which is as thin as the first-disk cartridge and is capable ofholding the second disk 51 in removable fashion, without increasing thestructural complexity and the size and cost of the recording/reproducingapparatus.

(b) The tray 53, which is slidable within the case 52 in directions inparallel to the direction of insertion into the recording/reproducingapparatus, can be set, as desired, either in the extended position toallow the loading and unloading of the second disk 51 or in theretracted position to allow the mounting and positioning thereof in therecording/reproducing apparatus; this construction makes it possible toset the tray 53 into the extended position in interlocking fashion withan eject action of the loading mechanism provided in therecording/reproducing apparatus for loading and unloading thesecond-disk cartridge. Furthermore, since the tray 53 has a secondopening hole 53d which, when in the retracted position, becomes exposedthrough the second opening hole 52d formed in the case 52, the turntable32 and head of the recording/reproducing apparatus can be insertedthrough the second opening holes 52d, 53d of the case 52 and tray 53.This enables the second disk 51 to be mounted and positioned directlyonto the turntable 32. As a result, it is possible to provide asecond-disk cartridge which enables a second disk 51 as contained in thesecond casing to be mounted directly into the recording or reproductionposition in a recording/reproducing apparatus, and which is as thin asthe first-disk cartridge and is easy to handle, the second disk 51 beingable to be loaded in or unloaded from the second-disk cartridge not onlyby manual operation but in interlocking fashion with an eject action ofthe recording/reproducing apparatus.

(c) The spring 55 is provided as the driving means to move the tray 53into the extended position to allow the loading and unloading of thesecond disk 51, in interlocking fashion with an unlocking action of thelocking unit; with this construction, the second-disk cartridge can beautomatically set into position to allow the loading and unloading ofthe second disk 51, just by pushing the locking unit either manually orusing a pin or the like provided in the recording/reproducing apparatus.Therefore, there is no need to move the tray 53 by manual operation orby using the loading mechanism in the recording/reproducing apparatus.This enhances the ease of operation and permits further simplificationof the construction of the recording/reproducing apparatus.

(d) Interlocking with the guiding action of the loading mechanism in therecording/reproducing apparatus to guide the second-disk cartridge orsecond casing, in particular, with the guiding action to guide thesecond casing toward the turntable 32, the second center hole 51a of thesecond disk 51 is centered with respect to the motor shaft 33 by thecentering unit, and the magnetic member 64 is attracted by the magnet 34provided in the turntable 32; thus, the second disk 51 can beautomatically centered and clamped in position. Therefore, therecording/reproducing apparatus need not have a special mechanism forcentering and clamping the second disk 51. Furthermore, since thecentering unit and the magnetic member 64 are constructed so that theydo not protrude beyond the external surface or -Z side surface of thecase 52, the construction does not involve an increase in the height ofthe recording/reproducing apparatus. Thus, it is possible to provide adisk cartridge having a disk clamping device which is capable ofautomatically centering and clamping the second disk 51 with no hub ontothe turntable 32 of the recording/reproducing apparatus, and allows areduction in the height of the recording/reproducing apparatus, withoutincreasing the structural complexity, cost, etc. of therecording/reproducing apparatus.

(e) In the present example, centering is accomplished by fitting thecentering part 62d of the clamp base 62 into the second center hole 51aof the second disk 51, and engaging the center hole 64a of the magneticmember 64 onto the motor shaft 33. The position of the centering part62d fitted into the second center hole 51a varies due to the diametricalaccuracy (usually, of the order of 0.1 mm) of the second center hole51a. However, since the elastic member 63 is compressed and deformed bythe attraction force by which the magnet 34 attracts the magnetic member64, the second center hole 51a is always held in contact with thecentering part 62d when the second disk 51 is centered and clamped inposition. In the prior known method, centering of the second disk 51with no hub is performed by using a mechanism in which a center conehaving a centering part inside the turntable is supported on a tensionspring (see FIG. 37). By contrast, in the present example, since thecentering is made possible just by providing the elastic member 63 onthe clamp base 62, a disk clamping device that is thin and simple inconstruction can be provided.

(f) Interlocking with the guiding action of the loading mechanism in therecording/reproducing apparatus to guide the second disk 51, inparticular, with the guiding action to guide the second disk 51 towardthe turntable 32, the disk clamping device is also guided toward theturntable 32. During this guiding process, centering of the second disk51 is performed by fitting the centering part 62d of the clamp base 62into the second center hole 51a of the second disk 51, and engaging thecenter hole 64a of the magnetic member 64 onto the motor shaft 33 thatis essentially designed to fit into the hubs 1d, 1d' of the first centerholes 1e, 1e' in concentric fashion. The centering part 62d fitted intothe second center hole 51a is subject to positional variation, but sincethe elastic member 63 is compressed and deformed by the attraction forceby which the magnet 34 essentially designed to attract the hubs 1d, 1d'attracts the magnetic member 64, the second center hole 51a is alwaysheld in contact with the centering part 62d when the second disk 51 iscentered and clamped in position. Thus, it is possible to provide a diskclamping device that is capable of automatically centering and clampingthe second disk 51 with no hub onto the turntable 32 of therecording/reproducing apparatus that is essentially designed to clampthe first disk 1 with hubs 1d, 1d' by magnetic attraction.

(g) Since the belt 54 and spring 55 are installed along the +X and -Yside faces of the tray 53 in such a manner as to overlap the locus ofthe moving tray 53, the provision of the belt 54 and spring 55 does notinvolve an increase in the height of the second-disk cartridge.

(h) Since the movement of the tray 53 is regulated by the damper 57, thetray moves slowly, and no injury will be caused if the user touches thetray in motion.

The present invention is not limited to the first example describedabove, but it will be appreciated that various modifications may be madein the invention. Other examples of the invention, Examples 2-12, willbe described below by comparison with Example 1. As a general rule,description of the construction, operation, reference numerals given indrawings, etc. will not be repeated where they are identical to thosedescribed in Example 1.

EXAMPLE 2

FIG. 28 shows a first-disk cartridge according to Example 2 of theinvention: shown here is an enlarged cross-sectional view of anessential portion (corresponding to portion B in FIG. 3) of thefirst-disk cartridge mounted and positioned in a recording/reproducingapparatus.

(1) In Example 1, the end portion of the motor shaft 33 is formed in anarc shape around its perimeter, as shown in FIG. 5; in the presentexample, on the other hand, the end portion 33a of the motor shaft 33 istapered. With this tapered end portion 33a, if there occurs asubstantial misalignment between the first center hole 1e of the firstdisk 1 and the center of the motor shaft 33, for example, accuratecentering can be accomplished since the first center hole 1e is guidedinto position by the tapered end portion 33a.

FIG. 29 shows a second-disk cartridge according to Example 2 of theinvention: shown is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a portion of thesecond-disk cartridge mounted and positioned in a recording/reproducingapparatus, with a tray in retracted position.

(2) In Example 1, the center hole 64a is formed in the magnetic member64, as shown in FIG. 25. Instead, in the present example, a center hole62h is formed in the clamp base 62, as shown in FIG. 29. The center hole62h in the clamp base 62 is formed so that the tapered end portion 33aof the motor shaft 33, when further extended, can be accommodated.Furthermore, a center hole 65h is formed in the clamp supporting plate65 to permit the end portion 33a of the motor shaft 33 to pass through.

(3) In Example 1, the centering part 62d is tapered, as shown in FIG.25. In the present example, the centering part 62d is formed in an arcshape or spherical shape, as shown in FIG. 29.

(4) In Example 1, the clamp supporting plate 65 is fixed to the clampbase 62 with flush head screws 66, as shown in FIG. 25. In the presentexample, the clamp supporting plate 65 is glued to the clamp base 62, asshown in FIG. 29.

(5) In Example 1, the Z-direction dimension of the elastic member 63 andcentering part 62d is made very small, as shown in FIG. 25. Thisdimension can be changed as required. In the present example, theZ-direction dimension of the elastic member 63 and centering part 62d ismade relatively large, as shown in FIG. 29.

EXAMPLE 3

FIG. 30 shows a second-disk cartridge according to Example 3 of theinvention: shown is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a portion of thesecond-disk cartridge mounted and positioned in a recording/reproducingapparatus, with a tray in retracted position.

The first-disk cartridge of this example is identical in construction tothat of Example 2.

(1) In Example 1, the clamp supporting plate 65 is fixed to the clampbase 62 with flush head screws 66, as shown in FIG. 25, but other fixingmethod may be used. In the present example, a supporting part 62z isformed on the clamp base 62. The connection between the clamp base 62and the upper half 52a is accomplished by elastically deforming anelastic deforming part 52z of the upper half 52a and thereby allowingthe supporting part 62z to fit into position.

(2) In Example 1, the magnetic member 64 made of magnetic stainlesssteel is provided separately from the clamp base 62, as shown in FIG.25. An magnetic member of another form may be used. In the presentexample, the clamp base 62 itself is formed from magnetic stainlesssteel, as shown in FIG. 30, so that it can also serve as the magneticmember. Alternatively, the clamp base 62 may be formed from soft ironand treated with rust preventive plating. In this construction, thevolume of the clamp base 62 as the magnetic member can be made large,which enhances the magnetic properties and increases the clamping forcefor clamping the second disk 51.

(3) In the present example, as in Example 2, a center hole 62h is formedin the clamp base 62 so that the tapered end portion 33a of the motorshaft 33, when further extended, can be accommodated.

(4) In the present example, as in Example 2, the centering part 62d isformed in an arc shape or spherical shape.

(5) In the present example, as in Example 2, the Z-direction dimensionof the elastic member 63 and centering part 62d is made relativelylarge.

EXAMPLE 4

FIG. 31 shows a second-disk cartridge according to Example 4 of theinvention: shown is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a portion of thesecond-disk cartridge mounted and positioned in a recording/reproducingapparatus, with a tray in retracted position. FIG. 32 shows aperspective view of a magnet and a magnetic member.

The first-disk cartridge of this example is identical in construction tothat of Example 2.

(1) In Example 1, the clamp base 62 is formed from magnetic stainlesssteel. In the present example, on the other hand, the magnetic member 64is formed from a permanent magnet magnetized with four poles, i.e.magnetized in +Z and -Z directions alternately in increments of 90degrees, as shown in FIG. 32, as with the magnet 34 provided in therecording/reproducing apparatus.

FIGS. 33A to 33C are schematic diagrams for explaining the action of themagnet 34 and magnetic member 64. FIG. 33A shows the action of themagnet 34 and magnetic member 64 before clamping, and FIG. 33B shows themagnetic flux from the magnet 34 and magnetic member 64 during clamping,while FIG. 33C shows the magnetic flux from a magnet 34' and magneticmember 64', each magnetized in only one direction, during clamping.

In the above construction, when the magnetic member 64 is moved,together with the second disk 51, in the -Z direction by the action ofthe loading mechanism, if the N poles in the surface 34a of the magnet34 that faces the magnetic member 64 are opposite the S poles in thesurface 64a of the magnetic member 64 that faces the magnet 34(therefore, the S poles in the surface 34a are opposite the N poles inthe surface 64a), then the magnetic member 64 is attracted by the magnet34, as shown in FIG. 33B, to clamp the second disk 51 between them.

Conversely, if, as shown in FIG. 33A, the N poles in the surface 34a ofthe magnet 34 are opposite the N poles in the surface 64a of themagnetic member 64 (therefore, the S poles in the surface 34a areopposite the S poles in the surface 64a), the magnet 34 and magneticmember 64 repel each other. As a result, the turntable 32 (magnet 34)and the clamp base 62 (magnetic member 64) turn relative to each other,as shown by the arrows in FIG. 33A, until the position shown in FIG. 33Bis reached where the magnetic member 64 is attracted by the magnet 34 toclamp the second disk 51 between them.

In any middle position between the above two positions, since like polesrepel each other, the turntable 32 (magnet 34) and the clamp base 62(magnetic member 64) turn relative to each other, and enter the positionshown in FIG. 33B to clamp the disk in position.

If the magnetic member 64 is moved in the -Z direction with the N polesin the surface 34a of the magnet 34 positioned exactly opposite the Npoles in the surface 64a of the magnetic member 64 (therefore, the Spoles in the surface 34a are positioned exactly opposite the S poles inthe surface 64a), since there always occur slight inclination, magneticproperty variations, positional displacement, etc. during the movement,the turntable 32 and the clamp base 62 turn relative to each otherwithout fail. Therefore, there is no possibility of accomplishingclamping with like poles positioned opposite each other, but the disk isalways clamped when the position shown in FIG. 33B is attained.

In this case, as can be seen from the magnetic flux lines duringclamping shown in FIG. 33B, the flux lines emerging from the N poles inthe surface 34b of the magnet 34 and in the surface 64b of the magneticmember 64, substantially return to the S poles, adjacent to therespective N poles, in the same surfaces, without passing through areasof high magnetic resistance.

However, in the case of the magnet 34' and magnetic member 64'magnetized in only one direction (+Z direction), as shown in FIG. 33C,the flux lines emerging from the surface 64'b of the magnetic member 64'substantially pass through areas of large magnetic resistance from the+Z to the -Z side before entering the surface 34'b of the magnet 34.Thus, according to Example 4, the magnetic resistance of the magneticmember 64 and magnet 34 can be further reduced, and the clamping forcecan thus be further increased.

(2) In the present example, as in Example 2, a center hole 62h is formedin the clamp base 62 so that the tapered end portion 33a of the motorshaft 33, when further extended, can be accommodated. Furthermore, acenter hole 65h is formed in the clamp supporting plate 65 to permit theend portion 33a of the motor shaft 33 to pass through.

(3) In the present example, as in Example 2, the centering part 62d isformed in an arc shape or spherical shape.

(4) In the present example, as in Example 2, the Z-direction dimensionof the elastic member 63 and centering part 62d is made relativelylarge.

EXAMPLE 5

FIG. 34 shows a perspective view of a second-disk cartridge according toExample 5 of the invention, with a tray 53 in the retracted position.FIG. 35 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing the second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with thetray 53 in the retracted position.

The first-disk cartridge of this example is identical in construction tothat of Example 2.

(1) In Example 1, the second opening holes 52d, 53d are not formed onthe +Z side, as shown in FIG. 7, so that mounting and positioning ispossible only when the cartridge is inserted with the lower half 52bfacing the turntable 32. In the present example, on the other hand, thesecond opening hole 52d is formed also in the upper half 52a, as shownin FIG. 34, so that the cartridge can be mounted and positioned whetherit is inserted with the lower half 52b facing the turntable 32 or withthe upper half 52a facing the turntable 32.

In this case, while the second opening hole 52d, similar to that formedin the lower half 52b, is formed in the upper half 52a, the secondopening hole 53d of similar shape is not formed in the tray 53. This canbe considered as forming a second opening hole 53d in the tray 53 thatexposes the entire +Z side of the second disk 51. Further, a pair ofsecond positioning holes 52f is formed in the upper half 52a as secondpositioning means for the +Z side. These second positioning holes 52f onthe +Z side consist of a round hole and an elongated hole, andcorrespond in position and shape to the first positioning hole 2f. Thesecond positioning holes 52f serve to accurately position thesecond-disk cartridge when inserted with the upper half 52a facing theturntable 32. In this case, no particular positioning is performed forthe tray 53 itself, but the positioning of the tray 53 is determined bypositioning the upper half 52a. Therefore, the upper half 52a needs tobe positioned accurately.

Furthermore, contrary to the construction of Example 1, the secondopening holes 52d and second positioning holes 52f may be formed only inthe upper half 52a so that mounting and positioning is possible onlywhen the cartridge is inserted with the upper half 52a facing theturntable 32.

(2) In Example 1, the clamp supporting plate 65 is fixed to the clampbase 62 with flush head screws 66, as shown in FIG. 25, but other fixingmethod may be used. In the present example, a supporting part 62z isformed on the clamp base 62. In this case, a clamp support 35 is formedon the loading mechanism, and the supporting part 62z is fit into theclamp support 35.

(3) In the present example, the Z-direction dimension of the elasticmember 63 and centering part 62d is made larger than that in Example 2.

(4) In the present example, as in Example 2, a center hole 62h is formedin the clamp base 62 so that the tapered end portion 33a of the motorshaft 33, when further extended, can be accommodated.

(5) In the present example, as in Example 2, the centering part 62d isformed in an arc shape or spherical shape.

EXAMPLE 6

FIG. 36 is an enlarged cross-sectional view showing an essential portion(corresponding to portion B in FIG. 3) of a disk cartridge mounted andpositioned in a recording/reproducing apparatus, according to Example 6of the invention.

(1) In Example 1, the hubs 1d, 1d' of the first disk are attracted bythe magnet 34, and the first center holes 1e, 1e' are caused to engageon the motor shaft 33, to accomplish the centering, as shown in FIG. 5.On the other hand, in the present example, the first disk 1 consistsonly of substrates 1a, 1b bonded together and having a thickness of, forexample, about 0.6 mm, and does not have a hub, as shown in FIG. 36. Thefirst center holes 1e, 1e' of the first disk 1 are centered by thecentering part 36a of the center cone 36 which is urged in the +Zdirection by the spring 37 and mounted slidably along the motor shaft33. An E-ring 38 is fixed into a groove formed in the end portion of themotor shaft 33. The E-ring 38 limits the travel of the center cone 37 inthe +Z direction.

The clamp base 62 is rotatably supported on the support 35 of theloading mechanism, and the magnetic member 64 formed from a permanentmagnet fixed to the clamp base 62 is attracted by the magnet 34, toclamp the first disk 1 between them. The magnet 34 and the magneticmember 64 are each magnetized with eight poles, that is, in +Z and -Zdirections alternately in increments of 45 degrees, as shown in FIG. 38.Their action is substantially the same as described in Example 4, andwill not be repeated here. In the present example, as in Example 4, themagnetic resistance of the magnetic member 64 and magnet 34 can befurther reduced, and the clamping force can thus be further increased.

In Examples 4 and 6, the magnet 34 and the magnetic member 64 are eachmagnetized with four or eight poles, but it will be appreciated that thesame effect can be obtained as long as the magnet 34 and the magneticmember 64 are magnetized with an even number of poles, including two, sothat the magnet 34 and the magnetic member 64 can be brought togetherwith unlike poles facing each other. Therefore, the magnet 34 and themagnetic member 64 need only be divided into different regions ofdifferent magnetization directions so that unlike poles can be broughtopposite each other, and the magnetization direction need notnecessarily be changed at equal angular intervals.

FIG. 37 is an enlarged cross-sectional view taken along linecorresponding to line F-F' in FIG. 11, showing a second-disk cartridgemounted and positioned in a recording/reproducing apparatus, with a tray53 in the retracted position. FIG. 38 shows a perspective view of themagnet and the magnetic member.

(2) In Example 1, centering is performed by fitting the centering part62d into the second center hole 51a of the second disk 51, and engagingthe center hole 64a onto the motor shaft 33, and the second disk 51 isclamped by having the magnetic member 64 attracted by the magnet 34, asshown in FIG. 25. On the other hand, in the present example, centeringis performed by fitting the centering part 36a of the center cone 36into the second center hole 51a of the second disk 51, the second centerhole 51a having approximately the same diameter as that of the firstcenter holes 1e, 1e' of the first disk 1, and the magnetic member 64 isattracted by the magnet 34 to clamp the second disk 51 between them, asshown in FIG. 37.

In the present example, a center hole 62h, slightly larger in diameterthan the motor shaft 33, is formed in the clamp base 62, as shown inFIGS. 36 and 37, to enable the clamp base 62, etc. to be roughlycentered with respect to the motor shaft 33. This serves to suppress thevibrations, etc. caused when the clamp base 62, etc. are rotated offcenter.

EXAMPLE 7

FIG. 39 is a perspective view of a first-disk cartridge according toExample 7 of the invention, showing the condition in which thefirst-disk cartridge is not mounted in a recording/reproducingapparatus.

(1) In Example 1, the first opening hole 2d is also formed in the upperhalf 2a, as shown in FIG. 2, so that the first disk 1 can be mounted onthe turntable 32 whether the first-disk cartridge is inserted with thelower half 2b facing the turntable 32 or, conversely, with the upperhalf 2a facing the turntable 32. By contrast, in the present example, asshown in FIG. 39, the first opening hole 2d is not formed in the upperhalf 2a so that the first disk 1 can be mounted on the turntable 32 onlywhen the first-disk cartridge is inserted with the lower half 2b facingthe turntable 32.

EXAMPLE 8

FIG. 40 shows a perspective view of a tray of a second-disk cartridgeaccording to Example 8 of the invention.

(1) In Example 1, the tray 53 has a second-disk holding recess 53ccapable of holding the large-diameter (about 120 mm) second disk 51, asshown in FIG. 9. This construction can be modified as required. In thepresent example, as shown in FIG. 40, the second-disk holding recess 53cof the tray 53 consists of a second-disk holding recess 53c1 capable ofholding the large-diameter (about 120 mm) second disk 51, and asecond-disk holding recess 53c2 capable of holding a smaller-diameter(for example, about 80 mm) second disk 51. Therefore, the protrusions53h formed to support the non-data areas of the two different kinds ofsecond disks 51 consists of a protrusion 53h1 for supporting the outernon-data area of the larger-diameter second disk 51, and protrusions53h2 for supporting the inner and outer non-data areas of thesmaller-diameter second disk 51.

EXAMPLE 9

FIG. 41 shows a perspective view of a tray of a second-disk cartridgeaccording to Example 9 of the invention.

(1) As shown in FIG. 41, the second-disk holding recess 53c in thisexample can hold only a small-diameter (for example, about 80 mm) seconddisk 51. Inside the second-disk holding recess 53c are formedprotrusions 53h for supporting the inner and outer non-data areas of thesmall-diameter second disk 51.

EXAMPLE 10

FIG. 42 shows a perspective view of a first-disk cartridge mounted andpositioned in a recording/reproducing apparatus, according to Example 10of the invention.

(1) In Example 1, as shown in FIG. 2, only one opening hole 2d is formedto permit the insertion of both the turntable 32 and head. Thisconstruction can be modified as required. In the present example, a holefor insertion of the turntable 32 and a hole for insertion of the headare formed separately as shown in FIG. 42, and designated together asthe first opening hole 2d. This construction serves to increase therigidity of the first-disk cartridge.

FIG. 43 shows a perspective view of a tray 53 of a second-disk cartridgeaccording to the present example, and FIG. 44 shows a perspective viewof a lower half 52b (case) of the second-disk cartridge.

(2) In corresponding relationship to the above (1), two second openings53d and two second openings 52d are formed in the tray 53 and the lowerhalf 52b, respectively, as shown in FIGS. 43 and 44. Alternatively, thetray 53 and the lower half 52b may be formed with single second openings53d and 52d, respectively, as in Example 1, as shown in FIGS. 9 and 10.

EXAMPLE 11

FIG. 45 shows a perspective view of a tray 53 of a second-disk cartridgeaccording to Example 11 of the invention, and FIG. 46 shows aperspective view of a lower half (case) of the second-disk cartridge.

(1) In Example 1, the second opening hole 53d in the tray 53 and thesecond opening hole 52d in the lower half 52d are formed as closedholes. This can be modified as required. Basically, the second openingholes should only be formed larger than the first opening hole 2d so asto include the entire area corresponding to the first opening hole 2d.In the present example, the second opening holes 53d and 52d are madelarger than the first opening hole 2d and opened in the +X direction.

EXAMPLE 12

FIG. 47 shows a perspective view of a lower half 52b of a second-diskcartridge according to Example 12 of the invention.

(1) In Example 1, the lower half 52b shown in FIG. 10 is formed as aone-piece construction by molding ABS resin or the like. By contrast, inthe present example, the lower half 52b is constructed, for example, ofa lower half base 52α and lower half protruding parts 52β and 52γ. Inthis case, the lower half base 52α is formed from a metal plate such asa stainless steel plate, while the lower half protruding parts 52β and52γ having projections and depressions and complex in shape are eachformed in one piece from ABS resin or the like. After that, the lowerhalf protruding parts 52β and 52γ are bonded to the lower half base 52αby adhesion or other means. To position the lower half protruding parts52β and 52γ on the lower half base 52α for bonding, cylindrically shapedprojections (not shown) formed on the -Z sides of the lower halfprotruding parts 52β and 52γ are fitted into positioning holes 52yformed in the lower half base 52α.

In the present example, other parts than the lower half protruding parts52β and 52γ are formed directly in the lower half base 52α. Thepositioning recesses 52m and the slit-like recess 52v, for example, areformed in the lower half base 52α itself, and only the lower halfprotruding parts 52β and 52γ, which are difficult to form from metalsheets, are formed as separate parts, thus constituting the lower half52b with a minimum number of parts (three parts).

If mounting compatibility with the first-disk cartridge is to bepreserved, the lower half 52b needs to be constructed to hold a tray 53thereon, which inevitably requires the thickness of the lower half 52bbe reduced, as is apparent from FIG. 14 in Example 1. According to thepresent example, since the lower half base 52α can be formed from metal,sufficient rigidity can be secured even if the thickness is reduced. Onthe other hand, in Example 1, since the whole construction can be formedin one piece from ABS resin or the like, including the partscorresponding to the lower half protruding parts 52β and 52γ in Example12 having projections and depressions and complex in shape, the cost andthe number of parts can be reduced.

The same effect can be obtained if the upper half 52a also isconstructed partially from metal sheets.

(2) In Example 1, the step-like recesses 521, shown in FIG. 10, areprovided for smoothly guiding the tray 53 in X directions. By contrast,in the present example, slit-like openings 521 are formed as the guidemembers, as shown in FIG. 47, which engage on the protrusions (notshown) formed on the -Z side of the tray 53 and extending in Xdirection, allowing the tray 53 to slide smoothly in X directionsrelative to the lower half 52b, i.e., the case 52. The protrusions (notshown) on the tray 53 and the openings 521 formed in the lower half 52bare made shorter than the corresponding parts in Example 1 so that thelower half 52b will not be separated by the openings 521 at the -X side.

Besides the modifications of Example 1, as disclosed above in Examples2-12, the following modifications also fall within the scope of thepresent invention.

(1) In Example 1, the recess 2j in the first-disk cartridge and therecess 52j in the second-disk cartridge are formed substantiallyidentical in form, but this can be modified as required. For example,the recess 52j may be made larger than the recess 2j so as to includethe entire area corresponding to the recess 2j.

(2) In Example 1, the spring 55 as driving means is constructed from atension spring, but this can be replaced by other driving means. Forexample, the driving means may be provided on the loading mechanism inthe recording/reproducing apparatus, or the driving means may beconstructed from a spiral spring or a compression spring.

(3) In Example 1, the second-disk cartridge is specifically constructedto be compatible with recording/reproducing apparatus designed for usewith the first-disk cartridge. Instead, the second-disk cartridge may beconstructed specifically for other type of recording/reproducingapparatuses designed for use only with the second-disk cartridge.

(4) In Examples 1-12, the first disk 1 and the second disk 51 have beendescribed as optical disks, but it will be appreciated that any type ofdisk can be used. For example, phase-change optical disks, magneto-opticdisks, or removable magnetic disks may be used.

The present invention is not limited to the contents disclosed inExamples 1-12 or to the above enumerated modifications, but it will berecognized that many modifications may be made in the invention withoutdeparting from the spirit thereof.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

What is claimed is:
 1. A second-disk cartridge for use in a recording orreproducing apparatus capable of mounting and positioning therein afirst-disk cartridge in which a first disk is rotatably held in afirst-disk holding recess formed in a first casing, and for holdingtherein a second disk having an outer diameter equal to or smaller thanan outer diameter of said first disk, comprising:a second casing havinga second-disk holding recess for holding rotatably said second disk, andcapable of being set in either of first and second positions, the firstposition that allows loading and unloading of said second disk withrespect to said second-disk holding recess under a condition that saidsecond-disk cartridge is inserted into said recording or reproducingapparatus, and the second position that allows mounting and positioningof said second disk with respect to said recording or reproducingapparatus; second positioning means for positioning said second-diskcartridge, formed at least on one side face of said second casing set insaid second position, and identical in form to first positioning meansfor mounting and positioning said first-disk cartridge in said recordingor reproducing apparatus; and a second opening hole formed correspondingto a first opening hole formed in said first casing for permittinginserting therethrough of a head and a turntable of said recording orreproducing apparatus, a size of said second opening hole being the sameas said first opening hole or larger than said first opening, whereinsaid second casing comprisesa case having a second sub-opening hole of asize not smaller than the size of said second opening hole, and havingtherein a tray holding recess, and a tray having said second-diskholding recess formed therein, and having another second sub-openinghole for exposure to exterior thereof through the second sub-openinghole of the case in said second position, said tray being supported insaid tray holding recess movably in directions parallel to a directionof insertion into said recording or reproducing apparatus, said secondcasing being set either in said first position or in said secondposition by moving said tray in the directions parallel to the directionof insertion into said recording or reproducing apparatus.
 2. A diskcartridge according to claim 1, further comprising: a locking means forlocking said tray in said second position; and driving means for drivingsaid tray into said first position in interlocking fashion with anunlocking action of said locking means.
 3. A disk cartridge according toclaim 1, wherein at least a portion of said case is formed form a metalplate.
 4. A disk cartridge according to claim 1, further comprising:centering means, supported rotatably in said second casing at a positionopposite said turntable of said recording or reproducing apparatus, forconcentrically engaging a second center hole formed in said second diskonto a motor shaft that drives said turntable for rotation; and amagnetic member, formed from a magnetic material, fixed to saidcentering means and attracted by a magnet provided in said turntable,wherein said centering means and said magnetic member do not protrudebeyond an externally exposed surface of said second casing.
 5. A diskcartridge according to claim 4, whereinsaid centering means includes aclamp base supported rotatably in said second casing at a positionopposite said turntable of said recording or reproducing apparatus, andan elastic member, fixed to said clamp base and capable of elasticdeformation in a thickness direction of said second disk, for holdingsaid second disk against said turntable, at least one of said clamp baseand said magnetic member is provided with a centering part that engagesin said second center hole of said second disk, and a center hole thatis formed concentrically with said centering part and that engagesconcentrically on said motor shaft.
 6. A second-disk cartridge for usein an apparatus capable of mounting and positioning therein a first-diskcartridge in which a first disk is rotatably held, comprising:a casehaving a second sub-opening hole for permitting insertion therethroughof a head and a turntable of a recording or reproducing apparatus, andhaving therein a tray holding recess, and a tray having a second-diskholding recess for holding rotatably said second disk, said tray beingsupported in said tray holding recess and movable in directions parallelto a direction of insertion into said recording or reproducing apparatusto enable setting in either of first and second positions, the firstposition that allows loading and unloading of said second disk withrespect to said second-disk holding recess under a condition that saidsecond-disk cartridge is inserted into said recording or reproducingapparatus, and the second position that allows mounting and positioningof said second disk with respect to said recording or reproducingapparatus, said tray further including another second sub-opening holefor exposure to exterior thereof through the second sub-opening hole ofthe case in said second position, wherein at least one of said case andsaid tray is provided with second positioning means for mounting andpositioning said second-disk cartridge in said recording or reproducingapparatus.
 7. A disk cartridge according to claim 6, further comprising:a locking means for locking said tray in said second position; anddriving means for driving said tray into said first position ininterlocking fashion with an unlocking action of said locking means. 8.A disk cartridge according to claim 6, further comprising: centeringmeans, supported rotatably in said case at a position opposite saidturntable of said recording or reproducing apparatus, for concentricallyengaging a second center hole formed in said second disk onto a motorshaft that drives said turntable for rotation; and a magnetic member,formed from a magnetic material, fixed to said centering means andattracted by a magnet provided in said turntable, wherein said centeringmeans and said magnetic member do not protrude beyond an externallyexposed surface of said case.
 9. A disk cartridge according to claim 8,whereinsaid centering means includes a clamp base supported rotatably insaid case at a position opposite said turntable of said recording orreproducing apparatus, and an elastic member, fixed to said clamp baseand capable of elastic deformation in a thickness direction of saidsecond disk, for holding said second disk against said turntable, atleast one of said clamp base and said magnetic member is provided with acentering part that engages in said second center hole of said seconddisk, and a center hole that is formed concentrically with saidcentering part and that engages concentrically on said motor shaft. 10.A disk cartridge according to claim 6, wherein at least a portion ofsaid case is formed from a metal plate.